Attrition-mill



(No Model.) 3 sheets-sheen' 1. ("1. 8u A. RAYMOND.

ATTRITION MILL. No. 403,215. Patented May 14, 1889.

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ATTRITION MILL.

No. 403,215. Patented May 14,1889.

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(No Modem G. 8v A. RAYMOND. ATTRITION MILL. No. 403,215. `Patented May'll, 1889.

@mi U ii W l En `UNITED STATES PATENT OFFICE.

GEORGE RAYMOND AND ALBERT RAYMOND, OF CHICAGO, ILLINOIS.

ATTRITION-MILL.

SPECIFICATION forming part of Letters Patent No. 403,215, dated May 14, 1889. Application iiled June-27, 1888. Serial No. 278,369. (No model.)

To all whom it may concern.-

Be it known that we, GEORGE 'RAYMOND and ALBERT RAYMOND, citizens of the United States, residing at Chicago, in the county of Oookand State of Illinois, have invented certain new and useful Improvements in Attrition-Mills, of which the following is a specification.

Our invention relates to that class of attrition-mills wherein the grinding or reduction of the material is accomplished by the impact of the fragments upon each other and the attrition of such fragments one by the other, or, in other Words, to that class of machines wherein the material under treatment forms the grinding-surfaces; and the object of our invention is to improve the construetion and operation of such machines, as hereinafter described and claimed.

In the accompanying drawings, Figure l is a partial view in front elevation of an att-rition-mill embodying one form of our improvements. Fig. 2 is a vertical cross-section on line 2 2 of Figs. l and 3. Fig. 3 is a plan view of the lower portion of the machine,

showing one of the revolving heads thereof in cross-section. Fig. 4: is a transverse sectional view on line A 4 of Figs. l and 3. Fig. 5 is a partial rear elevation of'a machine embodying some of the features shown in the former iigures, and part of the rear wall being broken away to expose portions of the interior construction. Fig. 6 isv a vertical cross-section on line 6 6, Fig. A5; and Fig. '7 is a detail showing in vertical section a revolving grinding-head provided with a removable grinding-ring.

The principal mechanical parts of our improved attrition-mill, as shown in the drawings, are constructed and arranged as follows: A base, A, supports the superstructure and rotatable shaft of the mill, and constitutes the lower section of the casing inclosing the operating parts. The base A is flat on its under surface to form abase for the machine and concave on its upper surface, whereby to constitute one portion of the grinding-chamber. Said base has at its upper extremity outwardly-projecting bolt-flanges a, to which are secured by bolt anges b segmental curved plates B, which form a part of the discharge-pipe G. The separating-chamber is A inclosed' at the top by a plate or covering, F, an extension of which, f, forms another portion of the throat of the discharge-pipe G. A

rotatable shaft, H, is journaled in suitable.

boxes centrally of the pulverizing-chamber, and has secured thereon one or more revolving heads I. Said heads, as shown in Figs. 2, 3, and 4, comprise a hub, t, a web, j, and a ianged periphery, J, projecting laterally from the web ,7' on each side. These heads are secured to rotate intermediate the hopper-openings and beneath the curved segmental parts B of the casing. They are all set on shaft H,

vand hence all revolve in the same direction.

Shaft H may be rotated by the application of belts to its pulleys h." Semi-cylindrical housings K inclose the upper parts of the revolving heads and protect the periphery of the same from the material to be reduced. The interiors of the hoppers of the pulveri'zingchambers and of the rear wall of the separating-chamber are protected by a lining, L, which is made in three parts, as shown, or otherwise suitably constructed. These linings are fitted to the interior wall of the casingand have anged edges Z extending Vinwardly in close proximity to the peripheries of the heads or beaters, thus forming in conjunction with the casing and heads or beaters annular chambers around the lower portion of the machine. Air-ducts M are employed to supply air to the separating-chamber, and vfor convenience these may be located at the rear of the hoppers and constitute one Wall thereof, Fig. 2. These air-ducts M communicate by the perforations rn. with the separating-chamber, and the air may also, in some conditions of the grinding, pass out of IOO the lower end of the ducts and into the pulverizing-chamber.

N represents the separating-chamber, and 0 the pulverizing-chambers.

It will be understood that the separat-ing chamber communicates with each of the pulverizing-chambers, and that in operation a suction-fan is connected to the discharge pipe G.

The front wall of the separating-chamber is lined by a corrugated chilled-iron plate, P. In the operation of the machine this plate will receive the violent impact of the particles undergoing reduction, and therefore should be quite heavy, so as to withstand the wearing effect of these particles. The upper part of the machine is hinged to the lower at Q, whereby when the bolts joining the upper and lower part-s at the bolt-flanges a b are removed ready access may be had to the wearing parts of the machine. penings are formed at R through the base A below the heads for the discharge of the reduced material, Fig. 2, accumulating there.

In operation the material is fed in through the hoppers D and passes directly into the pulverizing-chambers O between the revolving heads. By reference to Fig. Si it will be seen that said chambers O are greater in diameter than the revolvingheads, owin gto the shape of the linings L, and an important re sult is secured thereby, viz: The material, be-

ing fed continuously through t-hevhoppers D,

will accumulate in the pulverizing-chambers O and in the chambers of the revolving heads until the entire space is filled. During this iilling operation the material lying upon the bottom and sides of the chamber O will be at rest, while the material within the chambers of the revolving heads will be in motion, and the attrition of the fragments will follow from the impact of the moving mass upon the stationary mass. As the operation proceeds, a constant stream of mingled pulverized and unpulverized material will be thrown out ot the rear part of the pulverizing-chambers into the separating-chamber. During the operation a constant supply of air will be drawn by the action of the fan through the air-ducts into the separatilig-chamber, wheres by the pulverized material will be carried out through the discharge-pipe G, while the particles of material which are too large or heavy to be moved by the air-blast will drop back again into the pulverizing chamber. Any material which may find its way through the joints between the linings L and the revolving heads in the construction exhibited in Figs. l and 2 will pass out at the openings R in the base A.

In the type of machines shown in Figs. 5 and G we have introduced a modification, which consists in providing air-ducts S, com municatin g thro ugh the curved plates B, with the chambers or spaces Tbetween the periphery ot the heads and the base A. By this means air will be drawn by the action of the fan through said chambers, and any material which may accumulate therein can be drawn out and discharged into the separating-chainber, as shown in Figs. 5 and (5. By this arrangement all danger of the shutting oit of the supply of air by the stoppage of the perforations nz. is avoided, as constant currents of air are permitted to circulate under the heads and pass into the separatingchamber without passing through the material undergoingV comminution. In this modiiied con struction the perforations m, to admit air directly from the air-duct M to the separatingchamber, are dispensed with, and the base is not provided with the openings R, as all the material is discharged through the dischargepipe G. To assist in removing dust from the chamber T beneath the heads, lifts U are set transversely thereon, which, rotating close to the casing, will scrape any material out of the chamber and, assisted by the fan, will discharge it into the separating-chamber.

Deflecting plates V, Figs. 5 and (i, may be placed in the openin g above the chambers T, which will deiiect the iine material drawn from the said chamber outwardly into the separating-chamber.

In Fig. 7 l have shown a revolving head double cone-shaped in form and a lining, L, made to conform to the rear wall of the head. This head may be constructed in one piece or in two parts, X and Y, the latter having a boltfiange, y, fitted to the inner side of the other portion, to which it is secured by bolts, so that when it becomes worn it may be replaced without disturbing the other parts, which sustains no wear. It will be observed that the parts X and Y are frustums of cones, whose bases are joined together, thereby forming a pocket to receive and retain the material to be acted upon. The form of head shown in this figure is adapted for use in the end of the chamber, but when used in the body of the chamber it will be madedouble or with recesses on both sides.

It is apparent that in a machine organized as above described any number or width of pulverizing-chambers maybe provided by the use of the recessed heads, as said heads may be set at any distance apart desired, the linings being made to correspond. \V hen the heads are recessed on both sides, as shown, one head. may serve as means for operating the material on one side of two chambers formed on either side of it. One desirable result which we accomplish by our improved construction above described is that the pulverized material in the type of machine shown in Figs. 5 and (5 is confined entirely within the outside easing or shell of the machine until iinally discharged through the discharge-pipe Gr, thus preventing not only the waste of the material, but the annoyance and damage caused by the escape of the pulverized material.

XVe claim l. In an attrition-mill having a circular pulverizing-chamber, one or more recessed IOO IIO

heads mounted Within said chamber upon a rotatable shaft, a feed-opening communicatin gWith one side of the pulverizing-chamber, a separating-chamber communicating with the side of said pulverizing-chamber opposite the feed-openings, and an airduct communicatf ing with the pulverzingchamber, substantially as described.

2. In an attrition-mill having a circular pulverizing chamber, rotatable recessed heads mounted upon a common shaft Within the chamber, feed hoppers communicating With one side of the pulverizing-chamber, and

a separating-chamber communicating with the side of said pulverizing-chamber opposite the feed, and air-ducts communicating with the pulverizing-chamber7 substantially as described.

3. In an attrition-mill having a circular pulverizing chamber or chambers, a rotatable shaft mounted centrally Within said chambers and carrying heads recessed to receive material to be operated upon and adapted by their rotation to pulverize such material by its attrition upon the stationary material Within the pulverizing-chamber, and a separatingchamber communicating with the pulverizingfchamber, said chamber having av hard metallic lining to receive the impact of the iiying particles, substantially as described.

4. In an attrition-mill having a circular pulverizing chamber Within .which are mounted upon the same shaft rotatable recessed heads of less diameter than said chamber, flanged linings bridging` the space between said heads and the Wall of the chamber, feed hoppers communicating with one side of the pulverizing-chamber, a separatingchamber communicating With. the side of the pulverizing chamber opposite the feed entrance, and air-ducts communicating With the pulverizing chamber, substantially as described.

5. In an attrition mill having a circular pulverizing chamber Within which are mounted upon the same shaft. rotatable recessed heads of less diameter than said chamber, flanged linings secured to the peripheral Wall ofthe chamber between the heads, the flanges bridging the vertical space between the heads and the Wall, whereby passages are formed between the heads and the Wall, and air-ducts communicating with said passages, substantially as described.

6. A head for attrition-mills, double-coneshaped in form, whereby to provide a pocket or recess to contain material to be operated upon7 substantially as described.

GEORGE RAYMOND. ALBERT RAYMOND.

Witnesses:

C. C. LINTHICUM, T. D. BUTLER. 

